IMPROVEMENTS RELATING TO THE FORMATION OF CARTONS

Abstract: A continuous strip (1) of cardboard material is pre-cut to form a succession of carton blanks (2) interconnected at cutting points (3) which define the ends of the blanks. The strip (1) is formed into a roll which is mounted on a variable speed reel drive. The strip (1) is then fed by rollers to a cutting station (7) where a knife will operate to cut off individual blanks along the lines (3), whereafter the blanks will be formed into individual cartons (12).

Description: "Improvements relating to the formation of Cartons" A standard method of forming cartons is to feed pre¬ formed blanks individually from a stack to a carton forming machine. It is an object of this invention to provide an improved method of forming cartons. Accordingly, this invention provides a method of forming cartons wherein a strip of carton blanks is unwound from a pre-formed roll, an individual blank is cut from the end of the strip and is then passed to gluing and forming stations to transform the blank into a prepared carton. The preformed carton blanks can be fed very easily from a roll into a machine which cuts off the individual blanks and then forms the blank into a carton shape and glues overlapping portions together. The speed of operation of the system can readily be controlled by modifying, in particular, the rate at which the strip of blanks is fed from the roll. In the preferred arrangement the blank will move by advancing mechanisms to and from the various stations, and from the roll by a variable speed reel drive. The method of supplying the blanks in a strip from a roll is both efficient and relatively foolproof as compared with the feeding of individual blanks from a stack as great care has to be taken to ensure that the blanks are fed only one at a time and suitable indexing means has to be provided to allow for the decrease in the size of the stack. It is preferred that in carrying out the method the blanks in the strip should be preformed with a heat setting glue provided on the side flaps of the strip which are to be stuck down. As part of the forming process, the flaps of a blank can then be positioned over heaters at the gluing station. The blank will, ideally, be pressed into the prepared shape at the forming station by forming dies. The invention further extends to a roll of preformed carton blanks in a continuous strip which can be used in the method defined above and cartons formed by that method. The invention may be performed in various ways and a preferred embodiment will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 illustrates a portion of a strip of carton blanks on a roll, in accordance with the invention; Figure 2 illustrates a carton formed from one of the blanks of Figure 1; Figure 3 is a plan view of a carton forming machine using the roll of blanks shown in Figure 1; and Figure 4 is a side view of the machine shown in Figure 3. A continuous strip 1 of suitable material is pre-cut to form a succession of carton blanks 2 interconnected at cutting points 3 which define the ends of the blanks. The strip 1 is formed into a roll 4 which is mounted on a variable speed reel drive 5 as shown in Figure 3. The strip 1 is then fed by rollers 6 to a cutting station 7 where a knife will operate to cut off individual blanks along the lines 3. Side flaps 8 of the blanks will have had a hot melt adhesive applied during the printing and die-cutting stage. When the blank 2 is moved to a heating station 9, the adhesive on the flaps 8 will be melted. Then when the blank is advanced to a forming station 10 it will be pressed into a carton shape by a forming die 11 which will cause the glued flaps to stick to other parts of the blank. Converted cartons 12 of the form as illustrated in Figure 2 will then drop down below the forming station 10. The blanks will be indexed from the cutting station 7 and through the stations 9 and 10 by flaps 13 carried by a conveyor chain 14 which is indexed at the required speed to correspond to the rate at which the blanks 2 are fed from the roll 4.

Claims: CLAIMS 1. A method of forming cartons wherein a strip of carton blanks is unwound from a pre-formed roll, an individ¬ ual blank is cut from the end of the strip and is then passed to gluing and forming stations to transform the blank into a prepared carton. 2. A method according to Claim 1, wherein the blanks in the strip are preformed with a heat setting glue on side flaps thereof. 3. A method according to Claim 2, wherein the flaps of a blank are positioned over heaters at the gluing station. 4. A method according to any one of Claims 1 to 3, wherein the blank is pressed into the prepared shape at the forming station by forming dies. 5. A method according to any one of Claims 1 to 4, wherein the blank is moved by advancing mechanisms to and from the various stations, and from the roll by a variable speed reel drive. 6. A method of forming cartons substantially as herein described with reference to the accompanying drawings. 7. A carton as formed by the method of any one of Claims 1 to 6. 8. A roll of pre-formed carton blanks in a continuous strip and interconnected at cutting points which define the ends of the blanks, for use in the method as defined in any one of Claims 1 to 6.

Inventors: BRADLEY ALBERT JOHN, BRADLEY, ALBERT, JOHN
Applicants: BRADLEY ALBERT JOHN, BRADMAN LAKE LTD, BRADLEY, ALBERT, JOHN, BRADMAN-LAKE LIMITED
Application year: 1994
Main classification: B31B1
IPC codes: B31B1, B31B3